Method for Data-Flow Quality Control, a Related Receiver and a Related Transmitter

1. Method for data-flow quality control in a Digital Subscriber Line communications system including a transmitter, a receiver, and a Digital Subscriber Line intercoupling said transmitter and said receiver, said transmitter sending a data-flow to said receiver, said data-flow being modulated onto data-carriers according to a bit allocation indicative for the number of bits to be modulated on each data-carrier, said method comprising: measuring, at the receiver, the data-flow quality, transmitting a single request message to the transmitter, by the receiver, to decrease the bit allocation by a same amount for a plurality of data-carriers in case said data-flow quality is unsatisfactorily low, the request message is only a single value, the single value representing the amount by which to decrease the bit allocation; and decreasing, at the transmitter, said bit allocation accordingly.

2. Method for data-flow quality control according to claim 1 , wherein the same amount for decreasing said bit allocation for said plurality of carriers is a predetermined amount.

3. Method for data-flow quality control according to claim 1 , wherein the same amount for decreasing said bit allocation for said plurality of carriers is determined based on said dataflow quality.

4. Receiver for use in a Digital Subscriber Line communications system including a transmitter, said receiver and a Digital Subscriber Line intercoupling said transmitter and said receiver, said receiver being configured to receive a data-flow transmitted by said transmitter, said data-flow being modulated onto data-carriers according to a bit allocation indicative for the number of bits to be modulated on each data-carrier, said receiver comprising: a signal analysis part, configured to measure a data-flow quality; a request establishing part, having an input coupled to an output of said signal analysis part and configured to formulate a single request for said transmitter to improve said data-flow quality in case said data-flow quality is unsatisfactorily low; a request transmitting part, having an input coupled to an output of said request establishing part and configured to forward said request towards said transmitter, wherein the request establishing part of said receiver is configured to formulate said single request to improve said data-flow quality by decreasing said bit allocation by a same amount for a plurality of data-carriers, the request is only a single value, the single value representing the amount by which to decrease the bit allocation.

5. Receiver according to claim 4 , wherein said data-flow quality is a signal-to-noise ratio.

6. Transmitter for use in a Digital Subscriber Line communications system including said transmitter, a receiver and a Digital Subscriber Line intercoupling said transmitter and said receiver, said transmitter being able to send a data-flow to said receiver, said data-flow being modulated onto data-carriers according to a bit allocation indicative for the number of bits to be modulated on each data-carrier, said transmitter comprising: a request reception part, configured to receive from said receiver a request to improve a data flow quality; a request interpreting part, coupled with an input to an output of said request reception part and configured to interpret said request to improve said data-flow quality, wherein said transmitter further comprises: a bit allocation decreasing part, coupled with an input to an output of said request interpreting part and configured to decrease said bit allocation by a same amount for a plurality of data-carriers based on the request, the request is only a single value, the single value representing the amount by which to decrease the bit allocation.

7. Transmitter according to claim 6 , wherein said transmitter further comprises a bit swap performing part, coupled with an input to an output of said request interpreting part and configured to perform a bit swap on said data-carriers for continuing to transport said data-flow from said transmitter to said receiver after said decrease of said bit allocation.